The effect of digital physical activity interventions on daily step count: a randomised controlled crossover substudy of the MyHeart Counts Cardiovascular Health Study oleh Anna Shcherbina, MS, Steven G Hershman, PhD, Laura Lazzeroni, ProfPhD, Abby C King, ProfPhD, Jack W O'Sullivan, MBBS, Eric Hekler, PhD, Yasbanoo Moayedi, MD, Aleksandra Pavlovic, BS, Daryl Waggott, MSc, Abhinav Sharma, MD, Alan Yeung, MD, Jeffrey W Christle, PhD, Matthew T Wheeler, MD, Michael V McConnell, MD, Robert A Harrington, ProfMD, Euan A Ashley, ProfMBChB